Persistent warm Mediterranean surface waters during the Roman period.

Area of Science:

• Paleoclimatology
• Oceanography
• Mediterranean Studies

Background:

• Reconstructing past Sea Surface Temperature (SST) is challenging due to limited marine records and proxy uncertainties.
• The Roman Period (1 CE to 500 CE) is crucial for Mediterranean socio-cultural history, yet its climate remains unclear.

Purpose of the Study:

• To reconstruct Sea Surface Temperature (SST) evolution in the Sicily Channel during the Roman Period.
• To compare this new record with other Mediterranean SST data and Northern Hemisphere temperature reconstructions.
• To investigate the climatic conditions of the Roman Period in the Mediterranean.

Main Methods:

• Utilized Mg/Ca ratios from the planktonic foraminifer Globigerinoides ruber for SST reconstruction.
• Integrated new Sicily Channel data with existing SST records from the Alboran Sea, Minorca Basin, and Aegean Sea.
• Compared regional data with a Northern Hemisphere temperature reconstruction.

Main Results:

• A distinct regional warm phase occurred across the Mediterranean during the Roman Period.
• The Roman Period was the warmest of the last two millennia, with SSTs ~2°C above late-century averages in the Sicily and Western Mediterranean.
• A general cooling trend followed the Roman Period, with minor oscillations.

Conclusions:

• The Roman Period represents a significant climatic optimum in the Mediterranean.
• This Roman Climatic Optimum may be linked to the expansion and subsequent decline of the Roman Empire.
• Further research can explore the precise relationship between climate and Roman history.